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+/* OpenPC TC (Timer / Clock) support code
+ * (C) 2006 by Harald Welte <hwelte@hmw-consulting.de>
+ *
+ * PICC Simulator Side:
+ * In order to support responding to synchronous frames (REQA/WUPA/ANTICOL),
+ * we need a second Timer/Counter (TC2). This unit is reset by an external
+ * event (rising edge of modulation pause PCD->PICC) connected to TIOB2, and
+ * counts up to a configurable number of carrier clock cycles (RA). Once the
+ * RA value is reached, TIOA2 will see a rising edge. This rising edge will
+ * be interconnected to TF (Tx Frame) of the SSC to start transmitting our
+ * synchronous response.
+ *
+ */
+
+#include <lib_AT91SAM7.h>
+#include <AT91SAM7.h>
+#include <os/dbgu.h>
+
+#include "../openpcd.h"
+#include <os/tc_cdiv.h>
+#include <picc/tc_fdt.h>
+
+void tc_fdt_set(u_int16_t count)
+{
+ tcb->TCB_TC2.TC_RA = count;
+}
+
+void tc_fdt_init(void)
+{
+ AT91F_PIO_CfgPeriph(AT91C_BASE_PIOA, AT91C_PA15_TF,
+ AT91C_PA26_TIOA2 | AT91C_PA27_TIOB2);
+ AT91F_PMC_EnablePeriphClock(AT91C_BASE_PMC,
+ ((unsigned int) 1 << AT91C_ID_TC2));
+ /* Enable Clock for TC2 */
+ tcb->TCB_TC2.TC_CCR = AT91C_TC_CLKEN;
+
+ /* Clock XC1, Wave Mode, No automatic reset on RC comp
+ * TIOA2 in RA comp = set, TIOA2 on RC comp = clear,
+ * TIOB2 as input, EEVT = TIOB2, Reset/Trigger on EEVT */
+ tcb->TCB_TC2.TC_CMR = AT91C_TC_CLKS_XC1 | AT91C_TC_WAVE |
+ AT91C_TC_WAVESEL_UP |
+ AT91C_TC_ACPA_SET | AT91C_TC_ACPC_CLEAR |
+ AT91C_TC_BEEVT_NONE | AT91C_TC_BCPB_NONE |
+ AT91C_TC_EEVT_TIOB | AT91C_TC_ETRGEDG_RISING |
+ AT91C_TC_ENETRG ;
+
+ /* Reset to start timers */
+ tcb->TCB_BCR = 1;
+}
+
personal git repositories of Harald Welte. Your mileage may vary